| 摘要 |
A circuit arrangement for measuring mechanical displacements contains a capacitive sensor having two measuring capacitors (CA and CB) as well as a differential amplifier arrangement (4) for generating a voltage corresponding to the difference between the capacitances of the two measuring capacitors (CA and CB). In order to obtain a particularly high measurement accuracy, a controllable device (1) for charging and discharging the measuring capacitors (CA and CB) is connected to the capacitive sensor; a threshold detector (2) alternately monitors the voltages at the measuring capacitors (CA and CB) for overshoot of a prescribed threshold value and controls a bistable flip flop (Q2) which, for its part, controls a device (3) for alternately charging and discharging a first and second auxiliary capacitor (C1 and C2). It is possible with the aid of a delay element (Q3) downstream of the threshold detector (3) to delay discharging of the first or second auxiliary capacitor (C1 or C2) in such a way that the output voltage of the differential amplifier arrangement (4) is, independently of the stray capacitances of the measuring capacitors (CA and CB), proportional to the mechanical displacement detected by the capacitive sensor (Fig. 2). <IMAGE>
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